From: David Miller <davem@davemloft.net>
To: kuznet@ms2.inr.ac.ru
Cc: netdev@vger.kernel.org, shawn.lu@ericsson.com,
eric.dumazet@gmail.com, sol@eqv.ru
Subject: Re: [PATCH] tcp resets are misrouted
Date: Fri, 12 Oct 2012 13:53:43 -0400 (EDT) [thread overview]
Message-ID: <20121012.135343.2054104958323622117.davem@davemloft.net> (raw)
In-Reply-To: <20121012143417.GA8481@ms2.inr.ac.ru>
From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Date: Fri, 12 Oct 2012 18:34:17 +0400
> After commit e2446eaa.. tcp resets are always lost, when routing is asymmetric.
> Yes, backing out that patch will result in misrouting of resets for dead connections
> which used interface binding when were alive, but we actually cannot do anything here.
> What's died that's died and correct handling normal unbound connections is obviously a priority.
>
> Comment to comment:
>> This has few benefits:
>> 1. tcp_v6_send_reset already did that.
>
> It was done to route resets for IPv6 link local addresses. It was a mistake to
> do so for global addresses. The patch fixes this as well.
>
> Actually, the problem appears to be even more serious than guaranteed loss of resets.
> As reported by Sergey Soloviev <sol@eqv.ru>, those misrouted resets create a lot of
> arp traffic and huge amount of unresolved arp entires putting down to knees NAT firewalls
> which use asymmetric routing.
>
> Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Applied and queued up for -stable, thanks!
prev parent reply other threads:[~2012-10-12 17:53 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-12 14:34 [PATCH] tcp resets are misrouted Alexey Kuznetsov
2012-10-12 15:56 ` Debabrata Banerjee
2012-10-12 17:31 ` Shawn Lu
2012-10-12 17:47 ` Banerjee, Debabrata
2012-10-12 17:58 ` Shawn Lu
2012-10-12 17:53 ` David Miller [this message]
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